What Are Exterior Wall Coatings?

Exterior wall coatings are decorative treatments formulated for exterior masonry surfaces. They primarily have two main functions. Firstly they provide an attractive finish to the exterior of a building (internal wall coatings also exist). The second main function is to provide low maintenance and long life spans so they are usually very hard wearing and durable. Exterior wall coatings, therefore, tend to be quite high-end systems that use high quality and often expensive ingredients.

Exterior coatings are normally applied much thicker than traditional exterior paint (up to 40 times the thickness depending on the system). This makes them very weather resistant and helps to increase the life span of the coatings. The extra thickness also helps to cover any imperfections or scars that a wall may have whereas traditional paint is very thin and any scars are clearly visible underneath the thin paint film.

There are quite a few manufacturers producing a range of different systems with different features such as elastomeric or anti carbonation etc so it is important to specify the right system for the given situation and wall surface. It is therefore vital to discuss this in detail with the installation company or project manager etc.

Exterior wall coating systems tend to have a high resin content which can give attributes such as great elasticity and flexibility and brilliant adhesion qualities. Examples of some resins that can be found in various coating systems would be Pliolite, Alkyd, Polyester and Acrylic.

Manufacturers normally produce their coating products in a range of standard colours but if none of those standard colours are deemed to be suitable a special order can normally be placed and a coating can be produced to any colour (there is often a minimum quantity required for this though).

Exterior wall coatings are also available in a range of textures. These start from smooth (untextured) coatings that will look like normal paint, to fine textures, coarse textures and heavy high build textures. Therefore it is important to see samples before committing to a particular system. The use of a texture can be very advantageous. For example, if you have a rendered wall where the render is solid and well adhered to the underlying surface but it has received many repairs in the past and there is a range of surface appearances or texture differences, crack scars etc, the application of an exterior wall coating system which incorporates a texture can often cover unsightly scars and imperfections and create an attractive and uniform finish.

Manufacturers often describe their coating systems as being “microporous”. This means that although the coating is very good at resisting any water penetration, they also allow the passage of water vapour so are breathable. This makes exterior coating systems very effective in instances of penetrating damp.

If you are interested in having an exterior wall coating system applied to your property please contact us for advice and to receive a free quotation. An example of an exterior wall coating installation can be seen below with further examples on our case studies page.